Plz suggest me a suitable code so that when i click on the 32bits value radio button it will call the subroutine 32bits_value()

You need to make a distinction here. While clicking on the radio button is a client-side event, the actual function lies on the server.
In order for a client-side event to trigger a server action, you need to send a request to the server (aka Postback request). There are several ways of doing that, from reloading the whole page, to a specific AJAX call (which won't load the whole page).

However, If I'm reading your question right, there shouldn't be any actual call to the server, since you can run the calculations client-side via JavaScript.